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The German highway network is facing new challenges in the near future. The structures have to deal with increasing traffic loads, climate change effects and new requirements regarding sustainability while they are getting older and budget cuts can be expected. To guarantee a reliable highway network, it will be vital to adapt and enhance innovative approaches. Current bridge management relies on the results of conventional bridge inspections and thus has certain limitations when it comes to insufficient load bearing capacity and other systematic weaknesses. Therefore, new approaches for real time condition assessment of critical road infrastructure elements are to be developed.
In 2012 the fifth ESAR conference (Expert Symposium on Accident Research) was held in Hannover. ESAR is an international convention of experts, who analyze traffic accidents all over the world and discuss their results in this context, conducted at the Medizinische Hochschule Hannover every 2 years. It connected representatives of public authorities, engineers in automotive development and scientists and offers a forum with particular emphasis on In-Depth-Analyses of accident statistics and accident analyses. Special focus is placed on research on the basis of so-called "In-Depth-Accident-Investigations" [data collections at the sites of the accidents], which are characterized by extensive documentations of the sites of the accidents, of the vehicles as well as of the injuries, encompassing several scientific fields. ESAR aims at a multi-disciplinary compilation of scientific results and at discussing them on an international, scientific level. It is thus a scientific colloquium and a platform for exchanging information for all accident researchers. Experiences in accident prevention as well as in the complex field of accident reconstruction are stated and new research fields are added. Existing results of long-term research work in Europe, the US, Australia and Japan include different infrastructural correlations and give findings on population, vehicle population and driver characteristics, which offer a basis for recommendations to be derived and measures for increasing road safety.
The utilisation of secondary-safety systems to protect occupants has attained a very high level over the past decades. Further improvements are still possible, but increasingly minor progress is only to be had with a high degree of effort. Thus, a key aspect must be the impact to overall safety in an accident. If reliable information is available on an imminent crash, measures already taken in the pre-crash phase can result in a significantly great influence on the outcomes of the crash. With this background preventive measures are the key to a sustainable further reduction of the figures of crash victims on our roads. This paper aims to show a preventive approach that can contribute to lessening the consequences of a crash by creating an optimum interaction of measures in the fields of primary and secondary safety. To further enhance vehicle safety, driver assistant systems are already available that warn the driver of an imminent front-to-rear-end crash. The next step is to support him in his reactions or if he fails to react sufficiently, to even initiate an automatic braking when the crash becomes unavoidable. Automatic pre-crash braking can, in an ideal situation, fully prevent a crash or can significantly reduce the impact speed and thus the impact energy (and the severity of the accident). If a vehicle is being braked in the pre-crash phase, the occupants are already being pre-stressed by the deceleration. The information available about the imminent crash can be used to activate the belt tensioners and likewise other secondary safety systems in the vehicle right before the impact. The pre-crash deceleration also causes the front of the vehicle to dip. Conventional crash tests do not take this specific impact situation into consideration. This is why, for example, the influences of the pre-crash displacements of the occupants are not recorded in the test results. Furthermore, a reproducible representation of the benefit of the vehicle safety systems which prepare the occupants for the imminent impact is not possible. In order to demonstrate the functions of automated pre-crash braking and to investigate the differences during the impact as a consequence of the altered occupant positions as well as the initiation of force and deformations of the vehicle front, DEKRA teamed up with BMW to carry out a joint crash test with the latest BMW 5 series vehicle. It involved the vehicle braking automatically from a starting test speed of 64 km/h (corresponding to the impact speed set by Euro NCAP) down to 40 km/h. The test was still run by the intelligent drive system of the crash test facility. This required several modifications to be made to the test facility as well as to the vehicle. The paper will describe and discuss some relevant results of the crash test. In addition, the possible benefits of such systems will also be considered. The test supplemented the work of the vFSS working group (vFSS stands advanced Forward-looking Safety Systems).
Although the bus belongs to the safest traffic means, single accidents can be particularly severe and concern many passengers. Especially in case of fires a high number of injured and killed persons can be the outcome. Fire safety of buses therefore is of high importance. With the increase of synthetic and plastic materials as a material for the interior equipment of buses and coaches because of their ood mechanical properties combined with low weight, the question arises whether the safety level has decreased in case of a fire during the last years - also compared to other means of transport. Because of the combustible plastics and their ability to release a high amount of heat the main fire load in buses is no longer the fuel but the plastic materials which are also often easy to ignite. Besides the flammability of the equipments, the production of smoke, the smoke development and propagation and its toxicity for the people as well as the testing methods and limit values are of interest. For those reasons research projects were initiated on behalf of the German Federal Highway Research Institute. At the one hand the fire behavior of coach interiors was examined in general focusing on fire propagation as well as fire detection and signalling. As result, recommendations with regard to early fire detection systems for the engine compartments and on-board extinguishing equipment were elaborated. At the other hand research is carried out to examine heat release, smoke, smoke propagation and its toxicity due to burning bus interior materials. The paper describes which effective and economically reasonable fire safety requirements for interiors of buses would improve the current situation. Proposals for amendments of current requirements are recommended including the specification of appropriate limit values. In particular, it is taken into consideration which reasonable fire safety standards from other transport sectors, especially the rail sector, should be transferred to buses.
From literature well-known analyzes on risks, hazards and causes of accidents of older drivers are amended by the present study in which a comparison of the specific features of accident causes of older car drivers (older than 60 years) and of younger car drivers (under 25 years) is conducted. Mainly the question is pursued if specific errors, mistakes and lapses are predominant in the two different age groups. The analysis system ACAS (Accident Causation Analysis System) used hereby consists of a sequential system of accident causation factors from the human, the technical and the infrastructural field, whereupon for this study the influence of the human features on the accident development in two different age groups is of interest. ACAS is both an accident model and an analysis and classification system, which describes the human participation factors of an accident and their causes in the temporal sequence (from the perceptibility to concrete action errors) taking into consideration the logical sequence of individual basic functions. In five steps (categories) of a logical and temporal sequence the hierarchical system makes human functions and processes as determinants of accident causes identifiable. The methodology specifically focuses on the use in so-called "In-Depth" and "On-Scene" investigation studies. With the help of the system for each accident participant one or more of five hypotheses of human cause factors are formed and then specified by appropriate verification criteria. These hypotheses in turn are further specified by indicators in such manner that the coding of the causation factors by a code system meets the needs of database processing and are accessible to a quantitative data analysis. The first results of the descriptive comparison of the two age groups concern mainly differences in the functional levels "information admission/perception" (where the elderly drivers have more difficulties than the young ones) and "information processing/evaluation" (where the younger drivers show more problems). Concerning the cognitive function of "planning" the group of younger drivers seems to be more often involved in an accident because of excessive speed.
Real world accident reconstruction with the Total Human Model for Safety (THUMS) in Pam-Crash
(2013)
Further improvement of vehicle safety needs detailed analysis of real world accidents. According to GIDAS (German In-Depth Accident Study) most car to car front accidents occur at mid-crash severity. In this range thoracic injuries already occur. In this study a real world frontal crash with mid-crash severity out of the AARU database was reconstructed. The selected car to car accident was reconstructed by AARU by means of pc-crash software in order to get the initial dynamic accident conditions. These initial conditions were used to reconstruct the complete accident in more detail using FE models for the car structure and the occupants. Occupant simulations were performed with FE HIII-dummy models and the THUMS using Pam-Crash code. An initial THUMS validation was performed in order to verify the model-´s biofidelity by means of table-top test simulations. THUMS bone stiffness values were modified to match the real word occupant age. A comparison between driver and passenger restraint system loading was done, as well as an injury prediction comparison between the HIII-dummy model and THUMS response for both cases. Detailed comparison between the HIII-dummy models and THUMS regarding thoracic loading are discussed.
Die UNECE Regelung R58 regelt die Beschaffenheit und die Installation von Heckunterfahrschutzsystemen an schweren Güterkraftfahrzeugen, deren Ziel die Verbesserung der Kompabilität zwischen Pkw-Frontstrukturen und Lkw-Hecks ist. Dennoch verunglücken laut amtlicher Unfallstatistik allein in Deutschland rund 30 Pkw-Insassen in Heckauffahrunfällen auf Lkw tödlich, da diese Vorrichtungen hinsichtlich Einbauhöhe und Steifigkeit den Anforderungen des realen Unfallgeschehens nicht genügen. Das Ziel dieser Studie ist eine quantitative Abschätzung der möglichen Reduzierung der Verletzungsschwere mit Hilfe eines statistischen Modells, die durch eine Anpassung der geltenden Bestimmungen und die damit verbundenen technischen Veränderungen des bereits vorgeschriebenen Heckunterfahrschutzes zu erreichen wäre. In einer Nutzen-Kosten-Analyse wird die Wirtschaftlichkeit dieser Modifizierungen mit einem idealen Notbremsassistenten verglichen. Die Untersuchung orientiert sich dabei an den aktuell in der UN-ECE WP29/GRSG in Genf diskutierten Vorschlägen zur Anpassung der ECE-R58. Das verwendete ordinale Probit-Modell stellt einen Zusammenhang zwischen der Verletzungsschwere im auffahrenden PKW und erklärenden Größen her, in diesem Fall der kinetischen Energie des unterfahrenden Pkws und der strukturellen lnteraktion zwischen Lkw-Heck und Pkw-Front. Diese Maßnahmen könnten demnach 53 - 78% der Getöteten sowie 27 - 49% der Schwerverletzten bei diesen Unfallkonstellationen reduzieren, was pro Jahr 20 Getöteten und 95 Schwerverletzten entsprechen würde. Somit würde eine Modifikation einer bestehenden passiven Schutzmaßnahme an jährlich 100.000 neuzugelassenen Lkw und Anhängern bereits 20 Getötete adressieren. Im Vergleich dazu müssten jährlich 3 Millionen Pkw mit zusätzlicher Sensorik und Aktuatorik für einen idealen Notbremsassistenten ausgestattet werden, um im Idealfall alle Heckauffahrunfälle von Pkw auf andere Pkw oder Lkw und damit 53 Getötete zu vermeiden. Daher fällt auch das Nutzen-Kosten-Verhältnis deutlich zugunsten des verbesserten Heckunterfahrschutzes aus.
Bankette dienen im Wesentlichen der Verkehrssicherheit und dem Schadstoffrückhalt. Sie müssen dauerhaft standfest sein, damit abkommende Fahrzeuge, insbesondere schwere Lkw, nicht einsinken und verunfallen. Zum Grundwasserschutz müssen sie aber auch die Schadstoffe aus dem Straßenabfluss, der im Bankett versickert, zurückhalten. Der Schadstoffrückhalt im Bankett erfolgt vorwiegend durch mechanische Filtration. Diese wird vor allem durch die sandigen und schluffigen Kornfraktionen im Bankettmaterial bewirkt. Ist ihr Anteil aber zu hoch, nehmen die Standfestigkeit und die Tragfähigkeit ab. Es gilt, diese gegenläufigen Anforderungen an die Zusammensetzung von Bankettmaterial zu optimieren. Die Untersuchungsansätze und erste Ergebnisse der dazu beauftragten Forschung werden im Beitrag vorgestellt. Mit den Feinpartikeln aus dem Straßenabfluss und der Vegetation "wachsen" Bankette im Laufe der Jahre auf. Damit der Straßenabfluss nicht behindert wird und Aquaplaning auftritt, müssen Bankette regelmäßig geschält werden. Das bei dieser Reprofilierung anfallende Bankettschälgut ist grundsätzlich als Abfall einzustufen. Die dadurch bedingten Einschränkungen bei der Verwendung oder Verwertung sind in der "Richtlinie zum Umgang mit Bankettschälgut" beschrieben. Die dort aufgezeigten Möglichkeiten werden vorgestellt. Wenn das Bankettschälgut nicht innerhalb des Straßenbauwerks verbleiben kann, sollte es im Sinne der Ressourcenschonung verwertet werden. Bankettschälgut besteht zu circa 90 Masse-Prozent aus mineralischen Bestandteilen, die wieder für Bauzwecke genutzt werden können, wenn es durch eine geeignete Aufbereitung gelingt, die überwiegend pflanzlichen Anteile (Mähgutreste und Wurzeln) deutlich zu reduzieren. Aus einer Forschungsarbeit zu Kosten und Nutzen der Aufbereitung von Bankettschälgut werden der derzeitige Stand dargestellt und Perspektiven für eine werterhaltende Nutzung von Bankettschälgut aufgezeigt.
Europa bedeutet nicht nur eine gemeinsame Währung, sondern auch die Schaffung eines gemeinsamen Marktes verbunden mit dem Abbau von Handelshemmnissen. Dies bedeutet für Produkte aus dem Bereich Straßenausstattung, dass die unterschiedlichen nationalen Anforderungen durch einheitliche europäische Anforderungen ersetzt werden. Nationale Freigaben scheinen daher nicht im Sinne Europas zu sein, da durch zusätzliche nationale Anforderungen Handelshemmnisse eher aufgebaut als abgebaut werden. Die nationalen Freigaben im Bereich Straßenausstattung dienen jedoch nicht dem Aufbau neuer Handelshemmnisse, sondern der Umsetzung europäischer Vorgaben auf nationaler Ebene. Durch die mithilfe der nationalen Freigaben getroffene Vorauswahl können bereits während der Ausschreibungsphase Produkte erkannt werden, die die nationalen Randbedingungen nicht erfüllen beziehungsweise beim Einsatz zu Kompatibilitätsproblemen führen. Um dies zu verdeutlichen, werden exemplarisch für den Bereich Straßenausstattung die europäischen Anforderungen sowie die zusätzlichen Anforderungen aus den nationalen Freigaben für Fahrzeug-Rückhaltesysteme, Verkehrszeichenfolien und Fahrbahnmarkierungen betrachtet.
Within the automotive context camera monitor systems (CMS) can be used to present views of the traffic situation behind the vehicle to the driver via a monitor mounted inside the cabin. This offers the opportunity to replace classical outside rearview mirrors and therefore to implement new design concepts, aerodynamically optimized vehicle shapes and to reduce the width of the vehicle. Further, the use of a CMS offers the potential to implement functionalities like warnings or situation-adaptive fields of view that are not feasible with conventional rearview mirrors. Despite these potential advantages, it is important to consider the possible technical constraints of this technology and its effect on driver perception and behavior. On the technical side next to the field of view and die robustness of die system, aspects as its functionality at day and night as well as under varying weather conditions should be object to scientific investigation. Concerning human machine interaction, it has to be considered, that the perception of velocities and distances of approaching vehicles might be different for CMS as compared to conventional rearview mirrors and potential influences of factors as the Position of the displays or drivers' age should be taken into account. In order to shed light on these and further open issues, BASt is currently conducting a study that will cover the use of CMS under controlled conditions as well in real traffic. The first part of the study will focus on passenger cars, while in a second step the empirical investigation will be extended to heavy goods vehicles, where the potentials as well as the limitations of CMS might differ considerably. The presentation will cover the first part, with regard to the experimental design, implementation and initial results if already available.